An image reconstruction method comprises reconstructing an image using an iterative reconstruction method and computing a projection used in the reconstructing by summing ray increments between neighboring planes (P0, P1, P2, . . . ) parallel with a detector face (42) with stationary incremental blurring associated with each ray increment computed based on a distance between the neighboring parallel planes. A non-stationary blurring kernel may also be convolved at a plane closest to the detector face to generate a projection incorporating shift-variant blurring.